Due to a poor prognosis in untreated or ineffectively treated Central Retinal Vein Thrombosis, all work on this subject continues to be of considerable importance. The effect of anticoagulant and thrombolytic therapy was tested in 50 patients with central retinal vein occlusion, all with diagnosis confirmed by fluorescein angiography. Treatment groups were: 1) urokinase followed by heparin; 2) streptokinase followed by heparin; 3) heparin alone; and 4) no anticoagulant or thrombolytic agents. A marked improvement in visual acuity occurred in 57% of the 14 patients treated with urokinase and heparin, 42% of the 12 patients treated with streptokinase and heparin, 31% of the 13 patients treated with heparin alone and only one (9%) of 11 patients given neither of the anticoagulant or thrombolytic agents. Four additional patients with central retinal artery occlusion did not respond to treatment with Urokinase and heparin. Response in visual acuity did not correlate with fundus appearance. Bleeding complications were minor, and not attributable to thrombolytic agents. Working in close collaboration with an Australian group conducting clinical trials under an identical protocol, their results closely compare with those in our own study, with a 33% improvement in patients treated with streptokinase plus heparin; while 33% treated with heparin - only, remained the same. This series will continue accrual in a stratified randomized fashion. BIBLIOGRAPHIC REFERENCE: Kwaan, H.C., Dobbie, J.G., Fetkenhour, C.L. Clinical trial of Heparin, Urokinase and Streptokinase in Occlusive Retinal Vascular Disease. (submitted to New Eng. J. Med. 1975).